This invention relates to a buffer circuit receiving a TTL input and providing a C-MOS output. Ideally, the stand-by current when the buffer does not operate should be minimal; the difference in circuit speed between that based on a high input and that based on a low input should be minimal, as circuit speed does not overly depend on the input value; the difference in circuit speed between that with one Vcc level and that with a different Vcc level should be minimal; the set-up time and the hold time of address and of data should be stable and easy to control; and the margin of respective high and low input voltage levels should be adequate. Traditional buffer circuits in the prior art are less than ideal and there exists much room for improvement.